@@ -238,6 +238,7 @@ static int ext4_alloc_group_tables(struct super_block *sb,
ext4_group_t group;
ext4_group_t last_group;
unsigned overhead;
+ __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0;
BUG_ON(flex_gd->count == 0 || group_data == NULL);
@@ -261,7 +262,7 @@ next_group:
src_group++;
for (; src_group <= last_group; src_group++) {
overhead = ext4_group_overhead_blocks(sb, src_group);
- if (overhead != 0)
+ if (overhead == 0)
last_blk += group_data[src_group - group].blocks_count;
else
break;
@@ -275,8 +276,7 @@ next_group:
ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
group -= group_data[0].group;
group_data[group].free_blocks_count--;
- if (flexbg_size > 1)
- flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
+ flex_gd->bg_flags[group] &= uninit_mask;
}
/* Allocate inode bitmaps */
@@ -287,22 +287,30 @@ next_group:
ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
group -= group_data[0].group;
group_data[group].free_blocks_count--;
- if (flexbg_size > 1)
- flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
+ flex_gd->bg_flags[group] &= uninit_mask;
}
/* Allocate inode tables */
for (; it_index < flex_gd->count; it_index++) {
- if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk)
+ unsigned int itb = EXT4_SB(sb)->s_itb_per_group;
+ ext4_fsblk_t next_group_start;
+
+ if (start_blk + itb > last_blk)
goto next_group;
group_data[it_index].inode_table = start_blk;
ext4_get_group_no_and_offset(sb, start_blk, &group, NULL);
+ next_group_start = ext4_group_first_block_no(sb, group + 1);
group -= group_data[0].group;
- group_data[group].free_blocks_count -=
- EXT4_SB(sb)->s_itb_per_group;
- if (flexbg_size > 1)
- flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
+ if (start_blk + itb > next_group_start) {
+ flex_gd->bg_flags[group + 1] &= uninit_mask;
+ overhead = start_blk + itb - next_group_start;
+ group_data[group + 1].free_blocks_count -= overhead;
+ itb -= overhead;
+ }
+
+ group_data[group].free_blocks_count -= itb;
+ flex_gd->bg_flags[group] &= uninit_mask;
start_blk += EXT4_SB(sb)->s_itb_per_group;
}
@@ -615,7 +623,7 @@ handle_ib:
if (err)
goto out;
count = group_table_count[j];
- start = group_data[i].block_bitmap;
+ start = (&group_data[i].block_bitmap)[j];
block = start;
}
This is a note to let you know that I have just added a patch titled ext4: fix online resize with very large inode tables to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.20. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 55508c236d12a54d8a63a5ceda0be6d2ac2c2755 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso@mit.edu> Date: Sat, 15 Feb 2014 21:33:13 -0500 Subject: ext4: fix online resize with very large inode tables commit b93c95353413041a8cebad915a8109619f66bcc6 upstream. If a file system has a large number of inodes per block group, all of the metadata blocks in a flex_bg may be larger than what can fit in a single block group. Unfortunately, ext4_alloc_group_tables() in resize.c was never tested to see if it would handle this case correctly, and there were a large number of bugs which caused the following sequence to result in a BUG_ON: kernel bug at fs/ext4/resize.c:409! ... call trace: [<ffffffff81256768>] ext4_flex_group_add+0x1448/0x1830 [<ffffffff81257de2>] ext4_resize_fs+0x7b2/0xe80 [<ffffffff8123ac50>] ext4_ioctl+0xbf0/0xf00 [<ffffffff811c111d>] do_vfs_ioctl+0x2dd/0x4b0 [<ffffffff811b9df2>] ? final_putname+0x22/0x50 [<ffffffff811c1371>] sys_ioctl+0x81/0xa0 [<ffffffff81676aa9>] system_call_fastpath+0x16/0x1b code: c8 4c 89 df e8 41 96 f8 ff 44 89 e8 49 01 c4 44 29 6d d4 0 rip [<ffffffff81254fa1>] set_flexbg_block_bitmap+0x171/0x180 This can be reproduced with the following command sequence: mke2fs -t ext4 -i 4096 /dev/vdd 1G mount -t ext4 /dev/vdd /vdd resize2fs /dev/vdd 8G To fix this, we need to make sure the right thing happens when a block group's inode table straddles two block groups, which means the following bugs had to be fixed: 1) Not clearing the BLOCK_UNINIT flag in the second block group in ext4_alloc_group_tables --- the was proximate cause of the BUG_ON. 2) Incorrectly determining how many block groups contained contiguous free blocks in ext4_alloc_group_tables(). 3) Incorrectly setting the start of the next block range to be marked in use after a discontinuity in setup_new_flex_group_blocks(). Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> [ kamal: backport to 3.8 (context) ] Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- fs/ext4/resize.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) -- 1.8.3.2